"This transaction represents another important step in our ongoing debt reduction plan and follows the completion of our $3.1 billion sale of Eagle Ford shale assets in June," said Freeport's executive team in a statement.

"We remain committed to our balance sheet objectives while focusing on our large portfolio of high quality assets and resources, which provide strong current cash flows and have attractive growth characteristics."

The transaction includes all of FCX's interests in the Candelaria/Ojos mining district.

At the end of 2013 Candelaria/Ojos had consolidated recoverable reserves totaling 4.0 billion pounds of copper and 1.1 million ounces of gold. Consolidated production for the first six months of 2014 totaled 169 million pounds of copper and 42 thousand ounces of gold.

The transaction has an effective date of June 30, 2014, and is expected to close by year-end 2014, subject to regulatory approvals and customary closing conditions